/*
  Copyright (c) 2011 Arduino.  All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef String_class_h
#define String_class_h
#ifdef __cplusplus

//****************************************************************************
// @Project Includes
//****************************************************************************
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "dtostrf.h"

// When compiling programs with this class, the following gcc parameters
// dramatically increase performance and memory (RAM) efficiency, typically
// with little or no increase in code size.
//     -felide-constructors
//     -std=c++0x

//****************************************************************************
// @Class Definitions
//****************************************************************************
class __FlashStringHelper;
#define F(string_literal) (reinterpret_cast<const __FlashStringHelper *>(PSTR(string_literal)))

// An inherited class for holding the result of a concatenation.  These
// result objects are assumed to be writable by subsequent concatenations.
class StringSumHelper;

// The string class
class String
{
    // use a function pointer to allow for "if (s)" without the
    // complications of an operator bool(). for more information, see:
    // http://www.artima.com/cppsource/safebool.html
    typedef void (String::*StringIfHelperType)() const;
    void StringIfHelper() const {}

public:
    // constructors
    // creates a copy of the initial value.
    // if the initial value is null or invalid, or if memory allocation
    // fails, the string will be marked as invalid (i.e. "if (s)" will
    // be false).
    String(const char* cstr = "");
    String(const String& str);
    String(const __FlashStringHelper* str);
    explicit String(char c);
    explicit String(unsigned char, unsigned char base = 10);
    explicit String(int, unsigned char base = 10);
    explicit String(unsigned int, unsigned char base = 10);
    explicit String(long, unsigned char base = 10);
    explicit String(unsigned long, unsigned char base = 10);
    explicit String(float, unsigned char decimalPlaces = 2);
    explicit String(double, unsigned char decimalPlaces = 2);
    ~String(void);

    // memory management
    // return true on success, false on failure (in which case, the string
    // is left unchanged).  reserve(0), if successful, will validate an
    // invalid string (i.e., "if (s)" will be true afterwards)
    unsigned char reserve(unsigned int size);
    inline unsigned int length(void) const
    {
        return len;
    }

    // creates a copy of the assigned value.  if the value is null or
    // invalid, or if the memory allocation fails, the string will be
    // marked as invalid ("if (s)" will be false).
    String& operator = (const String& rhs);
    String& operator = (const char* cstr);
    String& operator = (const __FlashStringHelper* str);

    // concatenate (works w/ built-in types)

    // returns true on success, false on failure (in which case, the string
    // is left unchanged).  if the argument is null or invalid, the
    // concatenation is considered unsucessful.
    unsigned char concat(const String& str);
    unsigned char concat(const char* cstr);
    unsigned char concat(char c);
    unsigned char concat(unsigned char c);
    unsigned char concat(int num);
    unsigned char concat(unsigned int num);
    unsigned char concat(long num);
    unsigned char concat(unsigned long num);
    unsigned char concat(float num);
    unsigned char concat(double num);
    unsigned char concat(const __FlashStringHelper* str);

    // if there's not enough memory for the concatenated value, the string
    // will be left unchanged (but this isn't signalled in any way)
    String& operator += (const String& rhs)
    {
        concat(rhs);
        return (*this);
    }
    String& operator += (const char* cstr)
    {
        concat(cstr);
        return (*this);
    }
    String& operator += (char c)
    {
        concat(c);
        return (*this);
    }
    String& operator += (unsigned char num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (int num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (unsigned int num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (long num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (unsigned long num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (float num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (double num)
    {
        concat(num);
        return (*this);
    }
    String& operator += (const __FlashStringHelper* str)
    {
        concat(str);
        return (*this);
    }
    
    friend StringSumHelper & operator + (const StringSumHelper &lhs, const String &rhs);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, const char *cstr);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, char c);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, unsigned char num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, int num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, unsigned int num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, long num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, unsigned long num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, float num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, double num);
    friend StringSumHelper & operator + (const StringSumHelper &lhs, const __FlashStringHelper *rhs);
    
    // comparison (only works w/ Strings and "strings")
    operator StringIfHelperType() const
    {
        return buffer ? &String::StringIfHelper : 0;
    }
    int compareTo(const String& s) const;
    unsigned char equals(const String& s) const;
    unsigned char equals(const char* cstr) const;
    unsigned char operator == (const String& rhs) const
    {
        return equals(rhs);
    }
    unsigned char operator == (const char* cstr) const
    {
        return equals(cstr);
    }
    unsigned char operator != (const String& rhs) const
    {
        return !equals(rhs);
    }
    unsigned char operator != (const char* cstr) const
    {
        return !equals(cstr);
    }
    unsigned char operator <  (const String& rhs) const;
    unsigned char operator >  (const String& rhs) const;
    unsigned char operator <= (const String& rhs) const;
    unsigned char operator >= (const String& rhs) const;
    unsigned char equalsIgnoreCase(const String& s) const;
    unsigned char startsWith( const String& prefix) const;
    unsigned char startsWith(const String& prefix, unsigned int offset) const;
    unsigned char endsWith(const String& suffix) const;

    // character acccess
    char charAt(unsigned int index) const;
    void setCharAt(unsigned int index, char c);
    char operator [] (unsigned int index) const;
    char& operator [] (unsigned int index);
    void getBytes(unsigned char* buf, unsigned int bufsize, unsigned int index = 0) const;
    void toCharArray(char* buf, unsigned int bufsize, unsigned int index = 0) const
    {
        getBytes((unsigned char*)buf, bufsize, index);
    }
    const char* c_str() const
    {
        return buffer;
    }

    // search
    int indexOf( char ch ) const;
    int indexOf( char ch, unsigned int fromIndex ) const;
    int indexOf( const String& str ) const;
    int indexOf( const String& str, unsigned int fromIndex ) const;
    int lastIndexOf( char ch ) const;
    int lastIndexOf( char ch, unsigned int fromIndex ) const;
    int lastIndexOf( const String& str ) const;
    int lastIndexOf( const String& str, unsigned int fromIndex ) const;
    String substring( unsigned int beginIndex ) const
    {
        return substring(beginIndex, len);
    };
    String substring( unsigned int beginIndex, unsigned int endIndex ) const;

    // modification
    void replace(char find, char replace);
    void replace(const String& find, const String& replace);
    void remove(unsigned int index);
    void remove(unsigned int index, unsigned int count);
    void toLowerCase(void);
    void toUpperCase(void);
    void trim(void);

    // parsing/conversion
    long toInt(void) const;
    float toFloat(void) const;

    char* buffer;           // the actual char array
    unsigned int capacity;  // the array length minus one (for the '\0')
    unsigned int len;       // the String length (not counting the '\0')

    void init(void);
    void invalidate(void);
    unsigned char changeBuffer(unsigned int maxStrLen);
    unsigned char concat(const char* cstr, unsigned int length);

    // copy and move
    String& copy(const char* cstr, unsigned int length);
    String& copy(const __FlashStringHelper* pstr, unsigned int length);
};

class StringSumHelper : public String
{
public:
    StringSumHelper(const String& s) : String(s) {}
    StringSumHelper(const char* p) : String(p) {}
    StringSumHelper(char c) : String(c) {}
    StringSumHelper(unsigned char num) : String(num) {}
    StringSumHelper(int num) : String(num) {}
    StringSumHelper(unsigned int num) : String(num) {}
    StringSumHelper(long num) : String(num) {}
    StringSumHelper(unsigned long num) : String(num) {}
    StringSumHelper(float num) : String(num) {}
    StringSumHelper(double num) : String(num) {}
};

#endif  // __cplusplus
#endif  // String_class_h
